How they make curling stones

Now that the U.S. is the Olympic champion in curling, it behooves us to know how the curling stones are made. In fact, all curling stones used in the Olympics are made of granite mined on the uninhabited Scottish island of Ailsa Craig, which itself looks like a granite curling stone sitting in the Firth of Clyde:

The rights to make curling stones from Alisa Craig granite are held by the company Kays of Scotland, and their website (which has a shop where you can buy miniature curling stones, cufflinks, and even granite ice cubes) explains the materials used:

To create the best curling stones you require the finest materials and to this end we harvested 1500 tons from Ailsa Craig of the Common Green Granite and 270 tons of Ailsa Craig Blue Hone so as to satisfy our customers’ demands.

Our Kays Curling stones are made by matching the characteristics of these different granites and combining them enables us to produce the world class competition curling stones.

Over the years our craftsmen have researched the most suitable granites for the various parts of the curling stone.

This extensive research proved that Ailsa Craig Blue Hone granite is the most reliable and proven to be the only EFFECTIVE material for the stone’s running edge on todays modern ice.

The Ailsa Craig Common Green Granite is used for the body of the stone because its unique structure is more resistant to heat transfer, it copes better with condensation and does not splinter after contact with another stone in play, all of which badly affect Blue trefor curling stones.

The Blue Hone insert is fitted to the Ailsa Craig Common Green stone body, a technique we have perfected and called “Ailserts”.

The stones weigh between 38 and 44 pounds (17.24-19.96 kg). The brooms are special, of course, and a the members of a pair of curling shoes are different: a “slider shoe” (front) and a “gripper shoe” (back). Who knew?

This video, which I find mesmerizing, shows how the giant granite slabs are transformed into the shiny, spiffy-looking stones you see in competition.

Finally, to show how clueless I am, I found out only this morning, from a comment on this site, that there is women’s curling too. The reason I didn’t know it is because I saw only men’s curling on television, and nobody mentioned women’s curling. Let’s rectify this omission with some footage from the last Olympic championship in Sochi, when Canada took the gold medal by beating Sweden 6-3. This year (and I can’t find embeddable video), Sweden took the gold by beating South Korea, the home team, by a score of 8-3 (whatever that means!).

I did not find much explanation in the article, though it describes some important differences. I too am perplexed why women can’t do curling as well, or chess or bowling or snooker, etc.

One subtle difference might be sweeper to shooter transition. Maybe men are biologically capable of calming their heart rate to focus in shorter times. Could this be from more hunting or battle competitions? I do not know. I would have thought women have just as much if not more capable of recovering their focus after a short active period.

There are a lot of possibilities, and any of the following can be argued in one way or another to have an effect, but I think it’s number five that would actually make a significant difference. Please remember that these are all on average.

1. Men have more fast-twitch muscle.

2. Men have faster reaction time.

3. Men have greater grip strength.

4. Men have greater endurance, though this difference isn’t as pronounced as most physical differences between the sexes.

5. Men have better motor skills and spatial reasoning.

6. Your instinct regarding transition from sweeper to shooter is correct. Men have a lower standing heart rate, their heart rate increases faster during exertion, and their heart rate returns to normal faster.

With something like chess, better spatial reasoning is an enormous advantage, as chess at a high level requires imagining the board many steps ahead in many different formations. It’s also a matter of a greater number of men than women at the tail-ends of IQ distribution. To get anywhere significant in chess at the international level, one has to be an outlier. Men have greater variability of IQ: there are more men with extremely high intelligence than there are women, but there are also more men with extremely low intelligence. Since intelligence is correlated with success at chess, this is critical, but it should be noted that some of the greatest players ever likely did not have an IQ far above gifted. Bobby Fischer likely had an IQ in the 150’s, but Kasparov was likely in the high 130’s to low 140’s. Still, among the top crop of players, it’s very unlikely that a single person will be anywhere close to average.

Simply asserting 1 to 6 with no indication at all of evidence, no references, etc. are you?

For 1 and 3, there is plenty of fairly direct observation, maybe even scientific evidence.

But I think 4 is probably exactly false, i.e. if any difference, likely women have more endurance. My suspicion relates to sports such as ultra-marathons, which I pay little attention to now. (I did run badly a couple of 50 kms, hardly ultra, so took an interest way back.) But Ann Trason from a decade or two back might have been 3rd in the world, beating all but a couple of men in races over 80 km with significant accumulated elevation gain, despite the men’s likely superior strength and stride length.

Of course for endurance there might well be differences between 2-3 hour events like marathons, and 8-9 hour events like ironwoman triathlons.

In my main sport, nordic ski racing, it is clear that strength plays a big role, e.g. in ability to double pole uphill, that being faster than standard striding and kick-double -poling if you can keep that going without ‘stalling at too low speed in too high a gear’. Of course here it’s more strength to weight ratio than just strength. You can rip down the downhills faster as well, if you weigh more and have decent technique.

I think (strength/stride length) does the same in making men’s marathon records lower than women’s, not endurance.

I doubt that terribly reliable scientific evidence has ever been produced. The ‘jock-strap’ faculties in universities seem to produce a lot of dubious research–especially on diet.

Another source of ‘hearsay’ evidence of women’s endurance is accomplishments at Antarctic and major mountain expeditions in recent decades.

The evidence on one through three isn’t “fairly direct,” it is completely clear and has been demonstrated in studies for decades. I don’t think I need to post any.

For point four, studies show that women often have greater muscle endurance and resistance to fatigue of muscles overall, but not at the highest exertion rates, which would be the most relevant for sweeping in short bursts. Additionally, differences in fatigue are dependent on which muscle groups are being engaged. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2917609/

The longer an event is stretched out, though — like a marathon — the more these differences will be reduced, especially in an event like a marathon, and which most muscles in the body are engaged. With short bursts like in sweeping in curling, men’s faster return to normal heart rate is more important to endurance: http://www.acc.org/about-acc/press-releases/2014/03/27/12/29/allison-peak-hr-pr This article also confirms point six.

Point five has also been studied extensively. In the following collection of meta-analyses, you will find that, while men and women are very similar in most psychological variables, there are large differences between them in favor of men when it comes to mechanical reasoning, spatial visualization, and mental rotation: http://psycnet.apa.org/record/2005-11115-001 (you won’t be able to access the study without a subscription). There are many other studies I could post, like the following, which tested 90,000 women and 111,000 men from 53 nations, finding these differences in all the groups: https://pdfs.semanticscholar.org/c5d6/74d81ba368965c7d3311e1ca3ce655a2339e.pdf
That study can be accessed in full through that link.

Here are some studies on the differences in motor skills from point five:

Who says women can’t do curling as well as men? The article specifically disclaims any evidence either way saying

So while Internet commenters might claim that men’s superior strength means they’d always triumph in a curling battle of the sexes, there’s no entry in the record books that could confirm or deny that theory.

And the one statistic presented

As of Thursday evening, the men and the women had each played 23 games. An average of 12.56 points were scored in the men’s games, while the women’s average was 13.08 points.

How It’s Made is a totally engrossing series. I have often spent a short break from chores to watch an episode of how springs are made, or even drywall, or … whatever.
The music just goes with it, somehow.

Ailsa Craig is a volcanic plug, dating back to the (re)opening of the North Atlantic some 60 million years ago. Its unusual microcrystalline structure makes it distinctive, hence its use in curling stones. Erratics from Ailsa Craig show the spread of the ice sheets westwards across Ireland. More at http://nora.nerc.ac.uk/id/eprint/505002/1/Ailsa%20Craig.pdf

Ailsa Craig is also notable as the home to around 70,000 gannets (Morus bassanus)as well as a variety of other sea-birds. Eradication of rats on the island has enabled Puffins (Fratercula arctica)and Manx Shearwaters (Puffinus puffinus)to return to Ailsa Craig as breeding birds.
The island is located in the Firth of Clyde and when the Open Golf Championship is played at Troon it can be seen in the background to some of the tv coverage.

Don’t forget about mixed-doubles curling! A new event at this year’s Olympics, games are twice the speed and action as traditional games (that’s not meant to be facetious).

Congrats to the US men’s team for winning curling gold; they played great. It was a tough Olympics for most Canadian curlers, with both the men’s and women’s teams massively underwhelming. But we won the inaugural mixed-doubles medal via total domination! Watch highlights here: https://www.youtube.com/watch?v=qqXEvKF-lM8

IIRC, in olden days, you just wore regular leather-bottomed shoes, but put a rubber (not that meaning!) on the gripper shoe.

In such pre-historic times, I wore old Eaton’s catalogues under very long socks for hockey shin pads.

And there was little or no difference between nordic and alpine skis.

And the difference between nordic and cross-country skiing is that the former uses poles to produce more, sometimes all, speed; whereas the latter uses poles to keep the incompetent from falling on their posteriors.

And the appearance and 8,000 calories daily of nordic male ski racers is obvious proof that claims of impossibility for avoiding obesity purely by exercise and without diet are bullshit claims.

And the female nordic champion Margit Bjoergen is the best athlete that ever lived, male or female.

The lighter weight makes them stay in the air longer as air resistance helps keeps them aloft and I think the timing the jump is more important than power. In fact, some of the rules of jumping are designed so that there is less incentive for skiers to get too light (size limits on the skis for light weight jumpers).

After really big blizzards during my 99 years before retirement, I think 3 times I was able to ski down regular streets to my office. And fortunately, across the street was a pretty big open area to ski in, even a few little hills. Maybe weather or maybe too little outdoors and exercise, but it seems to be waning: Yesterday’s fun race in Parry Sound Ontario had 5 men 70+, but only 4 in each of 60-69 and 50-59.

“And the appearance and 8,000 calories daily of nordic male ski racers is obvious proof that claims of impossibility for avoiding obesity purely by exercise and without diet are bullshit claims.”

What an absurd statement – we all have ‘a diet’ and the amount of fat we carry depends on the balance of energy expended and energy consumed in our diet. Few people in ‘normal’ life can match the intensity, duration and frequency of exercise achieved by elite athletes (even if we had the will power to do so) as we have to do other stuff like sitting at desks, so consequently we have to eat much less if we are to avoid obesity. Controlling what you eat does not necessarily mean doing something faddish like only eating cabbage (or whatever) but if you want to lose weight without paying any attention to the calories you eat you are certainly making things extremely difficult for yourself.

(And I’m pretty sure that even though they necessarily eat a hell of a lot, those elite nordic skiers control their diets damn tightly).

But we’d need to see some of the ridiculous claims of the diet industry for what I think I’m getting at.

I’ll grant that those who exercise do pay attention to their tummies telling them they might feel nauseous if they don’t stop stuffing the spaghetti down the gullet. If that’s what you mean by “control their diets”, fair enough. But more likely the control is eating decent stuff, not worrying about the quantity.

Do you know how eg. our ‘UHT’ milk is made? You don’t want to know, and would not believe it anyway.
There is a team sport played in Holland and Belgium, where the teams consist in 3 women and 3 men. ‘Korfbal’ a kind of basketball (‘korf’ literally means ‘basket’) or netball.
It is said it is very old and the precursor of both basket- and netball. Would be nice to have a ‘mixed’ team sport at the Olympics.

Do you know how eg. our ‘UHT’ milk is made? You don’t want to know, and would not believe it anyway.
There is a team sport played in Holland and Belgium, where the teams consist in 3 women and 3 men. ‘Korfbal’ a kind of basketball (‘korf’ literally means ‘basket’) or netball.
It is said it is very old and the precursor of both basket- and netball. Would be nice to have a ‘mixed’ team sport at the Olympics.

Curling is quite interesting, but it makes me nervous to watch it. The shooter has to get the stone within a quarter of an inch of a target stone sometimes. But, what really makes me quiver, is how the sweepers manage to step, slip and stumble their way through a half a dozen stones without actually touching any with their feet. With the result that I’m always watching their footwork and miss the main action.
I think my favorite thing about curling is to hear a Canadian pronouncing the name of that area down at the end where all the smashing happens. The ‘haouws’.

I curled for a season in high school and enjoyed it despite lack of talent.
Here’s an interesting video on the physics of curling and the controversy about why the rock curls the way it does.
m.youtube.com/watch?v=7CUojMQgDpM

As soon as I heard that these stones only come from one place, I had several skeptical thoughts. Considering what happens to these stones during a match, what’s the big deal? I’m guessing some kind of high-tech plastic or ceramic would work better. I’m not buying any shares of Kays of Scotland.

Women’s curling is something I’ve been aware of from a very early age, as my mother was a curler and Dad and I had no choice in becoming very well informed of the intricacies of the game.
Dad said that he was going to paint a blue, white and red bullseye on the kitchen table so that she could demonstrate that day’s plays with the salt and sugar cellars and the sugar bowl.